摘要
油底壳表面辐射噪声占发动机总辐射噪声的20%左右,已成为降低发动机噪声的重要制约因素。以铸铝油底壳为例用有限元模型计算约束模态,并对结果进行综合性分析,识别出油底壳的结构薄弱位置。然后采取加筋,和底部进行形状上的结构优化,得到一种油底壳的最佳结构设计方案。经计算优化后的油底壳,第一阶约束模态频率提高了56%,且在2 000 Hz内的阶数减少了3阶。最后通过实验测试对比表明:发动机整机1 m声压级均值,在油底壳优化后,由原来的76.7 dB(A)降到75.6 dB(A),降低了1.1 dB(A),有一定的效果。
The radiation noise from oil pan＇ s surface is accounted for about 20 % in the total engine noise, which has become a noticeable restraint for engine noise reduction. In this paper, the finite element model for a cast aluminum oil pan is built, the constraint modes are calculated, and the vulnerable position of the oil pan is identified by the comprehensive analysis of the result. Then, an optimized oil pan design is derived by reinforcing the vulnerable position and improving the shape of the bottom of the oil pan. By calculating the optimized oil pan, it is found that the first order constraint modal frequency is increased by 56 %, and the order number is reduced by 3 in the range of 2 000 Hz. Finally, the results are compared with the experimental data. It is found that after the improvement, the mean lm sound pressure level of the engine is reduced from 76.7 dB （A） to 75.6 dB （A）, and the effect is obvious.
出处
《噪声与振动控制》
CSCD
2013年第6期115-119,共5页
Noise and Vibration Control
关键词
声学
模态计算
噪声分析
优化设计
acoustics
modal calculation
noise analysis
optimization design
